Relay with adjustable armature mounting



Aug. 12, F X. REES RELAY WITH ADJUSTABLE ARMATURE MOUNTING Filed March29 1944 ||V I 41| ii llllhl Illnm IIIIII FIG. I I Hlllllll FIG.. 10.

Patented Aug. 12, 1947 RELAY WITH ADJUSTABLE ARMATURE MOUNTING Frank X.Rees, Chili, N. Y., assignor to General Railway Signal Company,Rochester, N. Y.

Application March 29, 1944, Serial No. 528,556

(Cl. F75- 345) 4 Claims. l

This invention relates in general to relays oi the electromagnet type,and has more particular reference to an improved form of code followingrelay, adapted more particularly for use in connection with railwayoperation.

The relay of the present invention is an iniprovement in the form ofrelay disclosed in the Field application, Ser No. 351,003, iiled August3, 1940, now Patent No. 2,360,664, dated October 17, 1944, for Relay.

In the operation of relays of the type to which the present inventionrelates, there is a tendency upon movable contacts striking againstiixed contacts, to vibrate and bounce for a short period of time, duringwhich time the control circuits are not effectively made, and duringwhich time -there is excessive arcing at the contacts and burning of thepoints. This is particularly the case if the contacts carry heavycurrents and the relay is energized at a low level in the interest ofeconomy in operating costs. As a result, this faulty type of operationmaterially decreases the useful life of the relay contacts and reducesthe efficiency and economy of operation and maintenance.

With the above and other considerations in mind, it is proposed inaccordance with this invention, to provide a relay in whi-ch thesedefects are very largely obviated.

One of the objects of the present invention is to produce a relaywherein the movable contacts do not bounce or vibrate on the iixcontacts, whereby to vastly improve the operating characteristics ofrelays of this type.

Another object of the present invention is to produce an improved, yetsimple, form of adjusting means for the air gap between the armature andcertain of its cooperating pole pieces.

Further objects, purposes and characteristic features of this inventionwill appear as the description progresses, reference being made to theaccompanying drawings showing, solely by Way of example, and in nomanner whatsoever in a limiting sense, one form `which the invention canassume. In the drawings- Fig. l is a fragmentary sectional view, withparts shown in elevation, of a relay constructed in accordance with thepresent invention.

Fig. 2 is a fragmentary view of a detail of construction.

Fig. 3 is a fragmentary view, with parts shown in section, of air gapadjusting means.

Figs. 4-9 are fragmentary views showing various operative positions ofthe relay contacts.

Fig. is a View showing operative charac,-

teristics of a relay in accordance with this invention.

Fig. 11 is a view showing oscillograins of current conditions in aconventional relay and in a relay in accordance with the presentinvention.

Referring now to the drawings, a fragmentary portion of a relay, inaccordance with this invention, is shown in Fig. l. Only such parts ofthe relay will be described as are necessary for a completeunderstanding of this invention. The velay is shown as of the polarneutral type, but aan, of course, be of any other type, and is biased byspring means to make up its back contacts, whereby it responds only tocurrent of a particular polarity, to move its movable contact iingers soas to make up its front points. This operation is the same as set forthin the Field application, above referred to. A y

The relay includes a top plate TP, on which are supported theelectromagnetic operating means I2 and I3, and the permanent magnetoperating means III. The relay includes an armature I5, cooperating withthe electromagnet pole pieces I6 and II, and the permanent inagnet polepieces or shoes, I8 and I9. The armature rocks on a bearing comprising ahardened bearing block 20, extending across the permanent magnet poleshoes and received in slots in the shoes, as shown at 2| and 22 (Fig.3). Between the block 20 and the armature, and received in a V-shapedslot in the armature, is a cylindrical pivot rod 24.

The armature is shown in its spring biased position, that is, rockedclockwise so as to bear against the electromagnet pole shoe II byadjustable spring bias means `53 and 54. The armature is supported by aspring supporting means 25, suitably carried by, and adjustable on, asupport arm 26, carried by the top plate.

Connected to, and carried by, the armature is an operating arm 21,having one end fastened to the armature, as by bolts 28 and 29. Theoperating arm 2l terminates, at its outer end, in a tong-like jaw havingan upper portion 30, and a lower portion BI, which jaw receives, andholds in compressed, pretension fashion, spaced contact ngers 32 and 33.

These contact fingers 32 and 33 constitute rnovable ngers which areoperated by the jaw portions 30 and 3|, by means ofthe armature of therelay, and cooperate with Xed contact lingers 35 and 36. The contactngers 35 and 3E carry contact points 31 and 33, and are backed up by`adjusting screws 39 and 40 carried by stiff, absolutely rigid arms 42and 43, whereby to make the back contacts absolutely lixed and unyeldingwhen the movable contacts strike them.

The movable contact fingers 32 and 33 are made of relatively thin, lightspringy material, are relatively short in length, and are connected atone end, as at 45, to a short light spring member 46, which, togetherwith arms 42 and 43, are carried by a contact block 41, connected as byscrews 48, to a bracket 49, supported from the top plate as by bolts B.

As shown in the drawings, the movable contact fingers 32 and 33, carrycontact points 5l and 52, for cooperating, respectively, with the fixedcontact points 31 and 38.

The armature is biased to its deenergized, or non-operative polarityposition, by the means 53 and 54. Thus, the relay, as shown in Fig. l,can be considered to be making up its back points, in which conditionthe movable contact point 5I, is in contact with the fixed contact point31.

Means are provided, in accordance with this invention, to readily adjustthe polar air gap between the armature and the permanent magnet poleshoes. The permanent magnets, as I4, are each received in a socketmember, 56, which constitutes the permanent magnet pole shoes I8, and isbolted to the top plate, as by means 51, as clearly shown in Fig. 1-

The permanent magnet, as I4, is received in a socket 58 in thisreceiving member, and is held against becoming loose by a spring lockingmeans 59, as shown in detail in Fig. 2. This spring locking means 59comprises a flat central portion with upturned ends 60 and 6l, drilledas at 82 and 63, to receive the ends of the permanent magnets. When theparts are assembled the upsprung ends 60 and 6I are sprung, as shown inFig. 1, between each permanent magnet and its receiving socket, and thusthe spring operates to hold the two permanent magnets in xed positionand free from all vibration and play.

Extending from the lower face of each receiving socket, as the socket58, is a drilled hole, which receives a threaded adjusting screw 64,which bears at its lower end against one end of the pivot bearing bar20. This screw and the corresponding one in the other socket, can bemoved in` wardly or outwardly to position the bearing bar 2U a greateror lesser distance from the lower face of the permanent magnet poleshoes, whereby to vary the gap between the armature and the permanentmagnet pole shoes. The adjusting screws, as 64, are held in adjustedposition by set screws, as 66.

From the above description it can be seen that very rigid and quiteimmovable back and front xed contact fingers and contact points areprovided for cooperation with movable contact fingers which arerelatively short and light. Hence, in making Contact with either of theiixed contact points, there is but little energy in the movable lingersto tend to produce vibration, or bouncing, with respect to the Iixedcontact points. Furthermore, the armature, with its operating arm 21 foroperating the movable contact lingers, does not carry the movablecontact iingers, and hence the mass of the armature is not involved intending to produce any bouncing, or vibration, upon making up of front,or back, points.

In Figs. 4-9 are shown various operative positions of the contacts ofthis invention, and it may be helpful to consider them somewhat indetail.

In Fig. 4, the movable contact fingers are shown separate, and entirelyfree, from the, operating arm 21. It can be seen that they are formed tohave a natural bias to position them in a widely spaced relation, of anextent considerably greater than the spacing between the jaw parts 33and 3|. Thus, when these movable fingers are pressed towards each otherso as to be received in the operating jaw parts, as shown in Fig. 5,there is a very considerable amount of trapped tension or pretension.This condition is shown in Fig. 5, and the operating arm 21 is shown inits position half-way between full deenergized, and energized,positions.

In Fig. 6 is shown the position of the contacts, and associated parts,when the operating arm 21 has moved the movable contact fingers so as topass just very slightly beyond the point wherc the movable point 5|touches the fixed point 3'! and thus to transfer the trapped tension inthe movable linger 32, to contact pressure between the two Contactpoints in contact with each other.

In Fig. 7 the parts are shown in the positions they assume when the backContact is fully made up. It can be seen that the operating arm 21 hasmoved somewhat further than as shown in Fig. 6, and that the upward jawpart 33, which in Fig. 6 is still in contact with its movable contactfinger 32, is now spaced therefrom (Fig. 7), whereby to, in eirect,largely separate the mass of the armature from contributing to anytendency for the contact points to vibrate or bounce. Also, furthercontact pressure has been developed.

In Fig. 8, the parts are shown in the positions assumed in moving fromfully making up its back point, as shown in Fig. 7, to having just madeup its front point. This corresponds to the showing in Fig. 6.

In Fig. 9 the parts are shown in the positions assumed when the frontpoint is fully made up, and full contact pressure is realized; and thiscorresponds to the showing in Fig. 7, where the back point is fully madeup and full contact pressure is realized.

In Fig. 10 is a diagrammatic showing of the above described operativecharacteristics of the contacts of this invention. Represented along thehorizontal axis AT, is armature travel, while represented along thevertical axis CP, is contact pressure. As seen by the curves in thisfigure, the contact pressure is at a maximum at the armature position b,which is the position of the armature when the back contact is fullymade up, as for instance, in the condition shown in Fig. 7. As thecontact lingers move toward making up the front contact, and just beforethey break contact with the back contact, the contact pressure is asshown at 68, and is the pressure produced by the trapped tension incontact finger 32, and as can be seen, is about one-half of what thepressure is when the points are fully made up.

Upon a very slight further movement toward the front contact makingposition, the pressure on the back point falls to Zero, as representedat B8. The condition when neither xed contact point is made up, and themovable fingers are intermediate the front and back fixed contactpoints, is represented in Fig. 10 at the zero portion 'l0 of the curve.The contact pressure curve 1l, for the front points, is identical withthe one just described. This portion 1l has a portion made up by thetrapped tension, and a further portion made up by further armaturetravel.

Referring now to Fig. 11, there are here shown two oscillograms, thelower of which represents contact current conditions in an improvedrelay in accordance with the present invention, while the upperrepresents the corresponding characteristics in a conventional type ofrelay. Such relay is one in which the contact ngers are carried by thearmature, and in which there is no pretension or trapped tension in thecontact fingers.

Referring iirst to the upper oscillogram, the tracing '12, is producedby an alternating current of 60 cycles and furnishes a suitable scalefor reading elapsed time. The other tracing in this oscillogramrepresents the amount of current flowing through a movable contactpoint, and hence is a measure, under fixed conditions of voltage, etc.,of the resistance between the movable contact point and its fixed point.The portions 13 of the curve indicates that the contacts are fully openand no current flows through the movable contact point. In other words,there is a sufficient gap, as when the contact points are open toprevent all current flow. The portion 14 of the curve represents currentflow at its highest level, and thus represents the condition with thecontacts fully made up, and with full pressure. In the conventionalrelay, on making up a movable point with a fixed point, there isconsiderable vibration and bouncing for a considerable period of time.During this time the resistance across the points varies widely from theminimum, when the contact pressure is fully established, to a resistanceequal substantially to that when the contacts are fully open.

In the oscillogram, the portion 'l5 of the curve, comprising a series ofvertical lines arranged closely side by side, and connecting the lowerand upper lines 13 and le, indicates that, for a period of time, thecontact point resistance varies back and forth from a maximum to aminimum. After this, as represented b-y the portion 'i6 of the curve,the resistance uctuates considerably, but within narrower limits thanearlier, and changes, over a period of two or three cycles of the 60cycle current, from a minimum resistance, to a very substantiallyincreased resistance.

As a result, it can be seen from this oscillogram that, upon making up amovable contact with a iiXed contact (in the conventional relay), thecircuits thus controlled, are not properly closed for a considerableperiod of time at the beginning of the circuit closed period, and thatduring this time a very considerable amount of sparking and .burning andeven mechanical wear, of the contact points, necessarily takes place.

Referring now to the lower oscillogram, the 60 cycle timing tracing isrepresented at 11, the maximum level of current flow is represented at'58, and the period of Zero current now is represented at 19. It can beseen from this oscillogram that no current flows when the contacts areopen and that, upon the movable contact touching the iixed contact, thecircuit is at once closed with the minimum resistance, so that, for theentire period of contact closed condition, current flows in the circuitat a uniform, and the highest, level. As a result, substantially allarcing and burning of contacts, and mechanical wear of the same, isobviated, and the relay is much longer lived, and more dependable. Also,the circuits controlled, as, particularly, in the case of a relayfollowing a relatively fast code, are controlled much more accuratelyand dependably.

Thus, in applicants relay, unlike the conventional relay, there is notendency, during mid i the order of about .013".

stroke and at the time contact is made, to vibrate or whip, because ofthe fingers being held, with trapped tension, in the operator.

Also, the anvil effect, i. e., the tendency for the finger to bounce 01Tof the fixed contact so generally present in conventional constructions,is largely eliminated in applicants relay, due to the high degree oftrapped tension in comparison with the small mass of the moving partsinvolved.

While the proportions, and relative amounts of movement, of the variousparts oithis relay, can be varied within any reasonable limits, withoutdeparting from the spirit of the present invention, it should beunderstood that the construction described above, and the relativelightness of the iingers, and amounts of trapped tension, and movements,are to a large extent an essential part of the present invention. Whilenot restricting the invention to any particular set of values, one setwhich has been found in actual practice, to work outI to distinctadvantage, may well be given. It is a relay constructed in accordancewith this particular set of values, that produced the oscillographreadings shown in the lower oscillogram of Fig. l1.

In this relay, the full contact finger pressure is 55 grams, while thetrapped tension is 30 grams. The travel from full contact pressure totrapped tension pressure, that is, on Fig. l0, the horizontally measureddistance from the point b to the point 63, is .025, and the movement,measured horizontally from the point 08, to the point @9, is somethingless than .001. rEhe movement over the period where Zero pressureexists, is in The spacing between the movable contact fingers 32 and 33,when they are open, as in Fig. 4, is about .110 while, when they arecompressed so as to be received in operator 2l, but still out of contactwith either front or back fixed contacts, as in Fig. 5, the spacingetween the fingers is about .070.

As indicated above, the relay of this invention is particularly adaptedto be used to follow coded current, often times of a high rate, and tobe energized from a track circuitl Thus, under varying Weatherconditions, the level of energy applied to the relay, and depended uponto produce proper relay operation, will vary widely from time to time.Furthermore, the utmost economy in energy consumption is sought.

Under conditions such as outlined above, the usual and conventionalrelay is often rather unsatisfactory, and is particularly so when thelevel of energization falls to its minimum. Under such conditions andrequirements, however, relays constructed in accordance with thisinvention, perform in a most satisfactory manner, and thus solve thevery difficult problem of providing a relay of satisfactory operativecharacteristics, even when employed so as to effect the maximum ofeconomy in energy consumption, and under conditions of widely varyingdegrees of energization,

The novel bearing structure illustrated more particularly in Figs. l and3 is claimed herein whereas the novel non-bounce contact structure isclaimed in divisional application, Ser. No. 646.632, iled February 9,1946.

The above rather specific description of one form which the presentinvention can assume, is given solely by way of example, and is notintended, in any manner whatsoever, in a limiting sense. It is to beunderstood that various modifications, adaptations and alterations may,from time to time, be applied to meet the requirements of practice,Iwithout in any manner departing 7 from the spirit or scope of theinvention, except as may be limited by the appended claims.

What I claim is:

l. In relays, in combination, a top plate, a pole piece extendingthrough and fastened to the plate, a faced pole shoe on one end of thepole piece, a core receiving socket in the other end of the pole piece,a receiving slot in the face of the shoe, a pivot bearing bar slidablein the slot, a threaded opening connecting the bottom of the socket tothe base of the slot, and an adjusting screw in the opening and bearingagainst the bar.

2. In relays, in combination, a top plate, two spaced pole pieces eachextending through and fastened to the plate, a faced pole shoe on oneend of each pole piece, a core receiving socket in the other end of eachpole piece, aligned receiving slots in the faces of the shoes, anelongated pivot bearing bar extending across the pole shoes and slidablyreceived in the slot, a threaded opening connecting the bottom of eachsocket to the base of its slot, an adjusting screw in each Opening andbearing against the bar, and a set screw for fixing the adjustedposition of each adjusting screw.

3. In relays, in combination, a top plate, two spaced pole piecesextending through and fastened to the plate, a pole shoe on one end ofeach piece, a core receiving socket in the other end of each piece,aligned receiving slots in the faces of the slices, an elongated pivotbearing bar slidable in the slots, a threaded opening connecting thebottom of each socket with the base of its slot, an adjusting screw ineach opening and bearing against the bar, a core received in each socketand having a shoulder for limiting its projection into the socket, meansfor holding the cores in their sockets, and spring bias means forholding the cores tight and including an elongated plate like member ofspring material extending from one core to the other and having its endspositioned between the core shoulders and the pole shoes, each said endhaving an opening to allow the core to pass therethrough and being bentat an angle to the plane of the body of the plate like member.

4. In relays, in combination, a top plate, two spaced pole pieces eachextending through and fastened to the plate, a faced pole shoe on oneend of each pole piece, a core receiving socket in the other end of eachpole piece, aligned receiving slots in the faces of the shoes, anelongated pivot bearing bar extending across the pole shoes and slidablyreceived in the slot, a threaded opening connecting the bottom of eachsocket to the base of its slot, and an adjusting screw in each openingand bearing against the bar.

FRANK X. REES.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS

